info.debatty.java.graphs

Interface GraphInterface<T>

Type Parameters:

T -

All Known Implementing Classes:

Graph, OnlineGraph

public interface GraphInterface<T>

Author:

Thibault Debatty

Method Summary

Methods

Modifier and Type	Method and Description
ArrayList<Graph<T>>	connectedComponents() Split the graph in connected components (usually you will first prune the graph to remove "weak" edges).
boolean	containsKey(Node node)
Iterable<Map.Entry<Node<T>,NeighborList>>	entrySet()
NeighborList	get(Node node) Get the neighborlist of this node
int	getK()
Iterable<Node<T>>	getNodes()
SimilarityInterface<T>	getSimilarity()
void	prune(double threshold) Remove from the graph all edges with a similarity lower than threshold
NeighborList	put(Node<T> node, NeighborList neighborlist)
NeighborList	search(T query, int K)
NeighborList	search(T query, int K, double speedup) Improved implementation of Graph Nearest Neighbor Search (GNNS) algorithm from paper "Fast Approximate Nearest-Neighbor Search with k-Nearest Neighbor Graph" by Hajebi et al.
NeighborList	search(T query, int K, double speedup, double expansion) Improved implementation of Graph Nearest Neighbor Search (GNNS) algorithm from paper "Fast Approximate Nearest-Neighbor Search with k-Nearest Neighbor Graph" by Hajebi et al.
NeighborList	searchExhaustive(T query, int K)
void	setK(int k)
void	setSimilarity(SimilarityInterface<T> similarity)
int	size()
ArrayList<Graph<T>>	stronglyConnectedComponents() Computes the strongly connected sub-graphs (where every node is reachable from every other node) using Tarjan's algorithm, which has computation cost O(n).
void	writeGEXF(String filename) Writes the graph as a GEXF file (to be used in Gephi, for example)

Method Detail

connectedComponents

ArrayList<Graph<T>> connectedComponents()

Split the graph in connected components (usually you will first prune the graph to remove "weak" edges).

Returns:

containsKey

boolean containsKey(Node node)

entrySet

Iterable<Map.Entry<Node<T>,NeighborList>> entrySet()

get

NeighborList get(Node node)

Get the neighborlist of this node

Parameters:

node -

Returns:

the neighborlist of this node

getK

int getK()

getNodes

Iterable<Node<T>> getNodes()

getSimilarity

SimilarityInterface<T> getSimilarity()

prune

void prune(double threshold)

Remove from the graph all edges with a similarity lower than threshold

Parameters:

threshold -

put

NeighborList put(Node<T> node,
               NeighborList neighborlist)

search

NeighborList search(T query,
                  int K)

Parameters:

query -

K -

Returns:

search

NeighborList search(T query,
                  int K,
                  double speedup)

Improved implementation of Graph Nearest Neighbor Search (GNNS) algorithm from paper "Fast Approximate Nearest-Neighbor Search with k-Nearest Neighbor Graph" by Hajebi et al.

Parameters:

query -

K - search K neighbors

speedup - (default: 4)

Returns:

search

NeighborList search(T query,
                  int K,
                  double speedup,
                  double expansion)

Improved implementation of Graph Nearest Neighbor Search (GNNS) algorithm from paper "Fast Approximate Nearest-Neighbor Search with k-Nearest Neighbor Graph" by Hajebi et al. The algorithm is basically a best-first search method with random starting points.

Parameters:

query - query point

K - number of neighbors to find (the K from K-nn search)

speedup -

expansion - (default: 1.01)

Returns:

searchExhaustive

NeighborList searchExhaustive(T query,
                            int K)
                              throws InterruptedException,
                                     ExecutionException

Throws:

InterruptedException

ExecutionException

setK

void setK(int k)

setSimilarity

void setSimilarity(SimilarityInterface<T> similarity)

size

int size()

stronglyConnectedComponents

ArrayList<Graph<T>> stronglyConnectedComponents()

Computes the strongly connected sub-graphs (where every node is reachable from every other node) using Tarjan's algorithm, which has computation cost O(n).

Returns:

writeGEXF

void writeGEXF(String filename)
               throws FileNotFoundException,
                      IOException

Writes the graph as a GEXF file (to be used in Gephi, for example)

Parameters:

filename -

Throws:

FileNotFoundException

IOException